50 engaged in barbaric act of raising ship (7)
I believe the answer is:
salvage
'act of raising ship' is the definition.
'salvage' can be an answer for 'act' (salvage is a kind of act). I'm unsure of the 'of raising ship' bit.
'50 engaged in barbaric' is the wordplay.
'50' becomes 'l' (Roman numeral).
'engaged in' means one lot of letters goes inside another.
'barbaric' becomes 'savage' (synonyms).
'l' placed into 'savage' is 'SALVAGE'.
Can you help me to learn more?
(Other definitions for salvage that I've seen before include "Rescued sunken cargo" , "Rescue (and recycle?)" , "Preserve" , "Restore" , "Retrieve goods from wrecked ship" .)